Reduced creatine-stimulated respiration in doxorubicin challenged mitochondria: Particular sensitivity of the heart

Institute of Cell Biology, ETH Zurich, CH-8093, Zurich, Switzerland.
Biochimica et Biophysica Acta (Impact Factor: 4.66). 12/2007; 1767(11):1276-84. DOI: 10.1016/j.bbabio.2007.08.006
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ABSTRACT Doxorubicin (DXR) belongs to the most efficient anticancer drugs. However, its use is limited by a risk of cardiotoxicity, which is not completely understood. Recently, we have shown that DXR impairs essential properties of purified mitochondrial creatine kinase (MtCK), with cardiac isoenzyme (sMtCK) being particularly sensitive. In this study we assessed the effects of DXR on respiration of isolated structurally and functionally intact heart mitochondria, containing sMtCK, in the presence and absence of externally added creatine (Cr), and compared these effects with the response of brain mitochondria expressing uMtCK, the ubiquitous, non-muscle MtCK isoenzyme. DXR impaired respiration of isolated heart mitochondria already after short-term exposure (minutes), affecting both ADP- and Cr-stimulated respiration. During a first short time span (minutes to 1 h), detachment of MtCK from membranes occurred, while a decrease of MtCK activity related to oxidative damage was only observed after longer exposure (several hours). The early inhibition of Cr-stimulated respiration, in addition to impairment of components of the respiratory chain involves a partial disturbance of functional coupling between MtCK and ANT, likely due to interaction of DXR with cardiolipin leading to competitive inhibition of MtCK/membrane binding. The relevance of these findings for the regulation of mitochondrial energy production in the heart, as well as the obvious differences of DXR action in the heart as compared to brain tissue, is discussed.

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Available from: Uwe Schlattner, Sep 27, 2015
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    • "Cardiolipin is a major phospholipid component of the inner mitochondrial membrane and is required for the activity of respiratory chain. It is rich in polyunsaturated fatty acids and is particularly susceptible to peroxidative injury [23]; furthermore , evidence has been reported showing a strong affinity of doxorubicin for cardiolipin [24]. The drug-phospholipid complex formation leads to an inhibition of mitochondrial enzymes involved in oxidative phosphorylation. "
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    ABSTRACT: Cardiotoxicity is an important side effect of cytotoxic drugs and may be a risk factor of long-term morbidity for both patients during therapy and also for staff exposed during the phases of manipulation of antiblastic drugs. The mechanism of cardiotoxicity studied in vitro and in vivo essentially concerns the formation of free radicals leading to oxidative stress, with apoptosis of cardiac cells or immunologic reactions, but other mechanisms may play a role in antiblastic-induced cardiotoxicity. Actually, some new cytotoxic drugs like trastuzumab and cyclopentenyl cytosine show cardiotoxic effects. In this report we discuss the different mechanisms of cardiotoxicity induced by antiblastic drugs assessed using animal models.
    BioMed Research International 02/2014; 2014:240642. DOI:10.1155/2014/240642 · 2.71 Impact Factor
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    • "Second, we used a classical hemolysis assay with red blood cells (RBC) to demonstrate that PCr protects RBC from noxious insults by doxorubicin (Fig. 6A), hypoosmotic stress (Fig. 6B) and saponin (Fig. 6C). Hemolysis induced by doxorubicin can serve as a model of membrane damage related to oxidative stress [60], [61]. Supraclinical doxorubicin concentration of 300 µM induced hemolysis over a 5 h observation period. "
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    ABSTRACT: A broad spectrum of beneficial effects has been ascribed to creatine (Cr), phosphocreatine (PCr) and their cyclic analogues cyclo-(cCr) and phospho-cyclocreatine (PcCr). Cr is widely used as nutritional supplement in sports and increasingly also as adjuvant treatment for pathologies such as myopathies and a plethora of neurodegenerative diseases. Additionally, Cr and its cyclic analogues have been proposed for anti-cancer treatment. The mechanisms involved in these pleiotropic effects are still controversial and far from being understood. The reversible conversion of Cr and ATP into PCr and ADP by creatine kinase, generating highly diffusible PCr energy reserves, is certainly an important element. However, some protective effects of Cr and analogues cannot be satisfactorily explained solely by effects on the cellular energy state. Here we used mainly liposome model systems to provide evidence for interaction of PCr and PcCr with different zwitterionic phospholipids by applying four independent, complementary biochemical and biophysical assays: (i) chemical binding assay, (ii) surface plasmon resonance spectroscopy (SPR), (iii) solid-state (31)P-NMR, and (iv) differential scanning calorimetry (DSC). SPR revealed low affinity PCr/phospholipid interaction that additionally induced changes in liposome shape as indicated by NMR and SPR. Additionally, DSC revealed evidence for membrane packing effects by PCr, as seen by altered lipid phase transition. Finally, PCr efficiently protected against membrane permeabilization in two different model systems: liposome-permeabilization by the membrane-active peptide melittin, and erythrocyte hemolysis by the oxidative drug doxorubicin, hypoosmotic stress or the mild detergent saponin. These findings suggest a new molecular basis for non-energy related functions of PCr and its cyclic analogue. PCr/phospholipid interaction and alteration of membrane structure may not only protect cellular membranes against various insults, but could have more general implications for many physiological membrane-related functions that are relevant for health and disease.
    PLoS ONE 08/2012; 7(8):e43178. DOI:10.1371/journal.pone.0043178 · 3.23 Impact Factor
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    • "These discrepancies could be due to the experimental design or protocol used in each study and/or tissuespecific differences. Indeed, Tokarska-Schlattner and colleagues [28] evaluated the in vitro effect of DOX on heart and brain mitochondria and the authors observed that both types of mitochondria are affected by DOX. However, the results concerning brain mitochondria probably do not occur in vivo because DOX does not cross the blood–brain barrier [12]. "
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    ABSTRACT: This study was aimed at investigating the effects of subchronic administration of doxorubicin (DOX) on brain mitochondrial bioenergetics and oxidative status. Rats were treated with seven weekly injections of vehicle (sc, saline solution) or DOX (sc, 2 mg kg(-1)), and 1 week after the last administration of the drug the animals were sacrificed and brain mitochondrial fractions were obtained. Several parameters were analyzed: respiratory chain, phosphorylation system, induction of the permeability transition pore (PTP), mitochondrial aconitase activity, lipid peroxidation markers, and nonenzymatic antioxidant defenses. DOX treatment induced an increase in thiobarbituric acid-reactive substances and vitamin E levels and a decrease in reduced glutathione content and aconitase activity. Furthermore, DOX potentiated PTP induced by Ca2+. No statistical differences were observed in the other parameters analyzed. Altogether our results show that DOX treatment increases the susceptibility of brain mitochondria to Ca(2+)-induced PTP opening and oxidative stress, predisposing brain cells to degeneration and death.
    Free Radical Biology and Medicine 09/2008; 45(10):1395-402. DOI:10.1016/j.freeradbiomed.2008.08.008 · 5.74 Impact Factor
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